A receiver is used in a lot of hearing equipment for listening to sounds. In headphones, a receiver is incorporated in a cover formed to cover the ears, and there have been known an intra-concha type (also referred to as an inner ear type) receiver used by inserting a receiver into the ear concha and a canal-type receiver used by inserting an ear piece of a receiver directly into the external auditory canal. Receivers of a type used by being inserted into the ears like the intra-concha type receiver and the canal-type receiver are collectively referred to as an inner type receiver. Those receivers are used in a telephone set such as a mobile telephone and a hearing aid in which a sound collected from a microphone is electrically amplified and thereafter transmitted to the eardrum by a receiver. In the receiver, a sound-emitter such as a speaker is stored in a housing, and the receiver is used by radiating a sound wave from the sound-emitter to the auricle, the opening of the external auditory canal, or inside the external auditory canal. When the canal-type receiver is used, an ear piece is required. Regarding headphones, documents concerning headphones utilizing the functions of the auricle are seen here and there.
In the prior art canal-type receiver, there is a problem that monaural hearing (that is hearing in one ear and also referred to as monotic hearing) is not clear and unnatural.
Meanwhile, in binaural hearing, it cannot be said that such a problem of such “lateralization” that sound is produced in the head is solved. Further, a receiver capable of identifying sound from above and sound from below has not been provided.
Patent Documents 1 and 2 disclose proposals for solving the problem of “lateralization”.